1. Field of the Invention
The present invention relates generally to fiber optic connectors, and more specifically, to a duplex fiber optic connector having positionable ferrules that allow the ferrules to be rotated between a first keyed position for simultaneous coplanar end face polishing, and a second keyed position for mating with a receptacle, optical device or another connector of complimentary ferrule configuration with proper end face contact.
2. Technical Background
A variety of optical connectors have been developed to facilitate the interconnection of optical fibers with other optical fibers, optical devices or the like. In this regard, a number of simplex, duplex and multi-fiber connectors including standard ferrules, such as SC, LC, FC, MU, MT and MTP, have been designed. A common type of connector includes an angled-physical-contact (APC) ferrule that is designed to make physical contact with another APC ferrule during the process of interconnecting optical fibers (i.e., mating opposing fiber optic connectors). The end face of an APC ferrule is disposed at a non-orthogonal angle, i.e., at an angle other than 90-degrees relative to the longitudinal axis defined by the ferrule. Typically, the end face of an APC ferrule is disposed at about an 8-degree angle relative to a plane that extends perpendicular to the longitudinal axis defined by the ferrule. In order to interconnect a pair of APC ferrules, the ferrules are positioned such that the angled end faces are complimentary to one another, that is, the forwardmost portion of the end face of one ferrule is preferably aligned with the rearward most portion of the end face of the other ferrule. In order to facilitate the proper alignment of the ferrules in this complimentary fashion, the connectors are mated in a specific manner. In certain APC connectors, a portion of the connector assembly includes a physical key, indicator or marking that is disposed in a predetermined relationship to the end face of the ferrule and is used to orient the connector relative to a mating connector.
APC ferrules may be preferred over physical-contact (PC) ferrules, as well as ultra-physical-contact (UPC) ferrules, because the angled end face of an APC ferrule advantageously reduces undesirable reflections of optical signals at the interface between the mating optical fibers, thereby decreasing losses and correspondingly increasing signal transmission. Conventional APC ferrules typically require that the amount of material removed from the ferrule to define the angled end face be precisely controlled so as to form the proper angled surface. In this regard, the removal of either too much or too little material during the process of polishing the end faces typically results in a misalignment of mating ferrules, which decreases signal transmission.
In conventional, industry standard LC or SC APC duplex connectors, the two ferrules are typically aligned parallel (side-by-side) such that the two end faces are not coplanar. This orientation is needed in order to mate the duplex connector with an industry standard connector having the same complimentary orientation. By aligning the ferrules side-by-side, with the ferrule end faces in different planes, it is not possible to simultaneously polish the two ferrule end faces in the same plane using conventional apparatus and processes. When assembling a hardened duplex fiber optic connector using conventional LC or SC APC ferrules, the design of the hardened connector does not allow the ferrules to be separated and their end faces oriented into the same plane for simultaneous polishing. By polishing the end faces individually, one end face may be polished differently than the other, thus resulting in connector-to-connector mating with improper end face contact and resulting signal loss. Accordingly, what is needed is a duplex hardened connector that allows the ferrules and their respective end faces to be aligned relative to one another for coplanar polishing, and thereafter moved to a mating position.
In particular, a new approach is needed for a hardened duplex fiber optic connector that allows the ferrules to be rotated such that the end faces may be positioned in the same plane for simultaneous coplanar polishing. Thus, a multi-position ferrule or ferrule holder is needed that allows each ferrule to be rotated between a first position in which the end faces of the ferrules are coplanar for polishing, and a second position that properly aligns the end faces for connector-to-connector mating with a corresponding duplex connector of like ferrule configuration. The first keyed ferrule position preferably allows both ferrule end faces to be polished at the same time using conventional apparatus and processes. Once the polish is complete, the ferrules are rotated to the second keyed position for connector mating.